Centrifuges

ABSTRACT

A continuous centrifuge having a balanced head mounted for axial rotation in bearings. A radially extending arm including a cell is mounted at its extremity to receive fluid from a source through a fluidtight bearing coaxial with one of the head bearings. Means are provided for the discharge of the fluid from the cell through a second fluidtight bearing coaxial with the other head bearing. Means automatically discharge accumulated solids from the cell during rotation of the head. The head may include a second arm including one or more further cells and means may be provided to circulate solid free fluid discharged from the first cell through said further cell or cells prior to discharge through the second fluidtight bearing.

United States Patent n 13,570,753

[ 72] Inventor Colin Kerby 1,101,548 6/1914 Hoffman 233/17 Pier St. Kilda, Victoria, Australia 1,621,475 3/1927 Cross 233/ l [21] Appl. No. 791,842 2,696,307 12/1954 Rush 233/11X [22] Filed Dec. 12, 1968 3,050,238 8/1962 Doyle et al 233/45X g2 g i lz g f g; Primary Examiner-William 1. Price h d y Austmlia Attorney-Wenderoth, Lind and Ponaok [54] CENTRIFUGES 10 Claims, 9 Drawing Figs.

[52] [1.8. CI. 233/11, 233/14, 233/26, 233/45, 233/47 [51] 1nt.-Cl B04b 9/00, 1304b 15/02 [50] Field ofSeai-ch 233/1,1l, 14,19, 20, 21, 23, 24, 26, 27, 45,46, 47

[56] References Cited UNITED STATES PATENTS 1,026,075 5/1912 Coombs 233/19 ABSTRACT: A continuous centrifuge having a balanced head mounted for axial rotation in bearings. A radially extending arm including a cell is mounted at its extremity to receive fluid from a source through a fluidtight bearing coaxial with one of the head bearings. Means are provided for the discharge of the fluid from the cell through a second fluidtight bearing coaxial with the other head bearing. Means automatically discharge accumulated solids from the cell during rotation of the head. The head may include a second arm including one or more further cells and means may be provided to circulate solid free fluid discharged from the first cell through said further cell or cells prior to discharge through the second fluidtight bearing.

This invention relatestocentrifuges and particularly to centrifuges for use in the continuous removal of suspended solids from fluids.

Several elaborate designs of equipment for this purpose have been proposed, particularly. for use in biological and physiological studies but in practice these proposals have proved unsatisfactory and extremely expensive.

it is accordingly the principal objective of this invention to provide a simple cheap and effective continuous centrifuge suitable for use in applications where sterile conditions must be maintained.

With the above stated principal objective in view, there is provided accordingly to the invention a continuous centrifuge comprising a balanced head mounted for axial rotation in bearings andhaving at least one radially extending arm including' a cell mounted at its extremity to receive fluid from a source through a fluidtight bearing coaxial with one of the head bearings, means for the discharge of said fluid from the cell through a second fluidtight bearing coaxial with the other head bearing, and means for automatically discharging accumulated solids from the cell during rotation of the head.

Conveniently the head may include a second arm including one or more further cells and means may be provided to circulate solid free fluid discharged from the first cell through said further cell or cells prior to discharge through the second fluidtight bearing.

Preferably the fluidtight bearings comprise a fixed metal tube in mating coaxial engagement with a Teflon (Registered Trade Mark) or similar material tube communication with the cell located in the rotary head.

In use the device permits the effective removal of suspended solids from a fluid circulating continuously through the cell or cells mounted in the head.

The invention will now be described with reference to the accompanying drawings, in which:

FIG. I is a general elevation of a practical arrangement of the invention,

FIG. 2 is a cross-sectional view taken on the line 22 of FIG. 1

FIGS. 3 and .4 are a part cross-sectional view of the bearing structure andcell carrier shown in FIGS. I. and 2,

FIG. 5 is a cross-sectional view taken on the line 5-5 of FIG.

FIG. 6 isan alternative construction of the centrifuge head shown particularly in FIG. 3,

FIG. 7 is a cross-sectional elevation of an alternative cell carrier to that shown in FIG. 4,

FIG. 8 is a cross-sectional view taken on the line 8-8 of FIG. 7, and

FIG. 9 is a cross-sectional elevation of a further alternative cell construction.

Referring now to the drawings a centrifuge suitable for use in physiological investigation is shown and whilst in this particular application the capacity of the device is quite small it is toibe understood that by suitable scaling it may be readily applied to operations of a greater magnitude.

The head of the device consists of a shaft 10 mounted for rotation in two spaced bearings 11, I2 and provided with a pulley I3 driven by a belt 14 from a variable speed motor 15 as'shown in FIG. 21.

Two diametrically opposed radially extending arms I6, 17 are located on the shaft ill and whilst these anns need not be ofequal length it is essential that the assembly is dynamically balanced to ensure vibration free rotation about the shaft 10.

Each arm 116, I7 is provided at its extremity with a cell carrier for reception of cells to be described in detail hereinafter. Adjacent each head bearing a fluid connector comprising a fixed stainless steel tube l8 and 28 is located, the axis of the tube being coaxial with the axis of the shaft, as shown in detail in FIG. 3.

The end of stainless steel tube 18 remote from the bearings .is connected with a source of biological fluid, for example an animal, via suitable tubing.

On the input side of the device a narrow bore Teflon (Registered Trade Mark) tube 119 is fitted over the end of the stainless steel tube 18 adjacent the head bearing and passes through an axial bore 2G in the shaft 10 through the arm 16 to a cell 21 located in the cell carrier. The cell 21 comprises a small cylinder 22 provided with a suitable closure 23 and having a conically shaped bottom or floor 24. The apex of the floor is provided with an aperture 25 normally sealed by a spring operated valve member 26.

The Teflon tube 19 extends through the closure 23 to the vicinity of the cell floor 24 and a second similar tube 27 extends through the closure from the vicinity of the interior top of the cell through the arm 16 back to the axial bore 20 to the output side of the device and is connected thereto in the manner previously described with reference to the fluidtight bearing on the input side.

A suitable tube from the bearing 11 on the output side leads back to the source of fluid, or elsewhere as required.

In operation the head comprising shaft 10 and arms l6, 17 is brought up to a rotary speed of for example 1600 r.p.m. by the motor 15 and fluid is pumped from the source (not shown) into the cell 21, and thence through the output side of the machine to return to the source or elsewhere via tubes 19 and 27. During this operation the Teflon tubes rotate on the respective stainless steel tubes 18, 28 of the fluidtight bearings without any significant wear; or fluid loss. To reduce any undesirable heat rise due to friction the stainless steel tube may be mounted in a suitable heat sink 29 and if desired the heat sinks 29 may be rotated by separate drive means to further reduce friction on the tubes 18 and 28. As rotation of the head proceeds any solids present in the fluid, for example blood cells, are deposited by centrifugal force on the conical floor 24 of the cell and the resulting solid free fluid returns to the fluid source or elsewhere. A solenoid operated cam 30 is provided in a convenient position on the mounting structure of the device and on operation of the solenoid the cam engages the spring operated valve member 26 on the cell 21 during rotation of the head to permit solids accumulated on the conical cell floor to be discharged through the aperture 25 therein, as shown in part in FIG. 5. The solenoid (not shown) may be programmed to operate at time intervals of any desired length or may be manually operated. While in its operative position the solenoid operated cam 30 will actuate the cell valve member 26 once during each rotation of the head and it will be obvious that by suitable design any desired solids discharge rate may be attained.

In an alternative arrangement a second cell or cells 31 may be located on the arm 17 as shown in FIG. 6 to study the effect of the solid free liquid on specimens held in the cell or cells 31 however in certain applications the second cell may not be necessary and is thus not to be considered as an essential integer of the device.

As shown in FIG. 6 each of the cells 31 communicates with the cell 21 in arm 16 via tubes 32 and discharge fluid via tubes 33 to output tube 24. .T he arm 17 is provided with a cell carrier member 34 which may be locked in position on the arm by closure 35.

FIGS. 7 and 8 show how the cell 21 may be modified to permit the use of a plurality of cells in the arm 17, the input tube 19 leading fluid to the cell 22 and tubes 32 leading fluid therefrom to the cell or cells 31 in arm 17.

In certain applications it may be necessary to collect the solids normally discharged from the cell 21 via orifice 25 and in this case a cell as shown in FIG. 9 may be used.

An alternative cell 36 is shown in FIG. 9 including fluid input and output tubes 19 and 27, a floor 37 and an intermediate flexible diaphragm 38 capable of deforming under the weight of solids deposited thereon during operation to fill the area 39 of the cell 36,.

In use cell 36 is fitted to arm 16 and a two way cock is fitted on the inlet side of the centrifuge at l8 FIG. I. A similar two way cock is fitted on the outlet side at 28.

A supply of fluid is pumped from the source, through the centrifuge.

Collection of solids takes place on flexible membrane 38 which distends into cavity 39 under centrifugal force, the outgoing fluid is solid free.

Harvesting is accomplished by stopping the centrifuge from time to time, this reduces the pressure acting on membrane 38 which tends to resume its original shape, i.e. flat and in so doing disturbs the solids which have been collected, so that when both two way cocks are operated in the other direction and a pressurized stream of fluid introduced into that side which had recently been the outlet side, the pressurized stream is able to mix with the solids and jet them out the side which has recently been he inlet side, to a receptacle, at completion of the harvest the two, two way cocks are turned to their former position ready for the next cycle.

It has been found in practice that the relatively simple fluidtight bearings described are quite durable and effective, similarly the solids discharge operation may be effected without any undesirable loss of the fluid medium.

I claim:

1. A continuous centrifuge comprising a balanced head mounted for axial rotation in bearings and having at least one radially extending arm including a cell mounted at its extremity to receive fluid from a source through a fluidtight bearing coaxial with one of the head bearings, means for the discharge of said fluid from the cell through a second fluidtight bearing coaxial with the other head bearing, and means for automatically discharging accumulated solids from the cell during rotation of the head.

2. A continuous centrifuge according to claim 1 wherein the head includes a second arm for the reception of a further cell or cells.

3. A continuous centrifuge according to claim 2 including means for circulating solid free fluid discharged from the first cell through said further cell or cells prior to discharge through the second fluidtight bearing.

4. A continuous centrifuge according to claim I wherein said fluidtight bearings comprise a metal tube in mating coaxial engagement with a tube in communication with said cell located in said head.

5. A continuous centrifuge according to claim 4 wherein said metal tube is mounted in a heat sink to absorb heat generated by friction during operation.

6. A continuous centrifuge according to claim 1 wherein said means for discharging of solids collected in said cell comprises a valve in said cell operable by a solenoid, said solenoid engaging said valve during rotation of said head.

7. A continuous centrifuge according to claim 6 including means to automatically actuate said solenoid at preset intervals.

8. A continuous centrifuge comprising a balanced head mounted for axial rotation in bearings, a radially extending arm on said head, a cell mounted in said arm, a first fluidtight bearing coaxial with one of said bearings, means for supplying fluid from a source to said cell through said first fluidtight bearing, a second fluidtight bearing coaxial with the other head bearing, means for :discharging said fluid from said cell through said second fluidtight bearing and means for automatically discharging accumulated solids from said cell during rotation of said head.

9. A continuous centrifuge comprising a balanced head mounted on a hollow shaft for axial rotation in bearings, a radially extending arm on said head, a cell mounted in said arm, means for supplying fluid from a source to said cell through said shaft, means for discharging said fluid from said cell through said shaft and means for automatically discharging accumulated solids from said cell during rotation.

10. A continuous centrifuge as set forth in claim 9, wherein a second radially extending arm is provided on said head and a cell is mounted in said second arm. 

1. A continuous centrifuge comprising a balanced head mounted for axial rotation in bearings and having at least one radially extending arm including a cell mounted at its extremity to receive fluid from a source through a fluidtight bearing coaxial with one of the head bearings, means for the discharge of said fluid from the cell through a second fluidtight bearing coaxial with the other head bearing, and means for automatically discharging accumulated solids from the cell during rotation of the head.
 2. A continuous centrifuge according to claim 1 wherein the head includes a second arm for the reception of a further cell or cells.
 3. A continuous centrifuge according to claim 2 including means for circulating solid free fluid discharged from the first cell through said further cell or cells prior to discharge through the second fluidtight bearing.
 4. A continuous centrifuge according to claim 1 wherein said fluidtight bearings comprise a metal tube in mating coaxial engagement with a tube in communication with said cell located in said head.
 5. A continuous centrifuge according to claim 4 wherein said metal tube is mounted in a heat sink to absorb heat generated by friction during operation.
 6. A continuous centrifuge according to claim 1 wherein said means for discharging of solids collected in said cell comprises a valve in said cell operable by a solenoid, said solenoid engaging said valve during rotation of said head.
 7. A continuous centrifuge according to claim 6 including means to automatically actuate said Solenoid at preset intervals.
 8. A continuous centrifuge comprising a balanced head mounted for axial rotation in bearings, a radially extending arm on said head, a cell mounted in said arm, a first fluidtight bearing coaxial with one of said bearings, means for supplying fluid from a source to said cell through said first fluidtight bearing, a second fluidtight bearing coaxial with the other head bearing, means for discharging said fluid from said cell through said second fluidtight bearing and means for automatically discharging accumulated solids from said cell during rotation of said head.
 9. A continuous centrifuge comprising a balanced head mounted on a hollow shaft for axial rotation in bearings, a radially extending arm on said head, a cell mounted in said arm, means for supplying fluid from a source to said cell through said shaft, means for discharging said fluid from said cell through said shaft and means for automatically discharging accumulated solids from said cell during rotation.
 10. A continuous centrifuge as set forth in claim 9, wherein a second radially extending arm is provided on said head and a cell is mounted in said second arm. 